Hugs ffi, sizeOf operator

I ran into a possible problem while testing some ffi code.
 This is with hugs compiled for cygwin or with the windows (msi)  version.
Hugs says: sizeOf x::CDouble is 4,
wheras 'C' says sizeof(double) is 8.

I ~~think~~ I see what the problem is with sizeOf.  I am using the
new hierarchical libs, and it defines sizeOf by hardcoding the sizes rather
then asking 'c' like the previous versions did. And sizeOf Double is coded
as 4 in libraries\Foreign\Storable.hs
Is there something simple I just don't understand? 

As a side note, is alignPtr implemented somewhere?

(Alastair, I already sent this to you, but didnt sent to the list.)

Gratefully, 
  Ron